For more than a month the FBI had been desperately searching for Carole Sund, and on March 18 they found her. In a small clearing off Highway 108 near Sonora, Calif., agents discovered the scorched shell of the red Pontiac recently driven by Sund, 42. The mother of four had disappeared on a trip from her home in Eureka to Yosemite National Park with her daughter Julie, 15, and a family friend from Argentina, Silvina Pelosso, 16. In the car's trunk were the charred remains of Sund and one other person, whose identity the FBI has not yet announced. "We don't know for sure how the car came to be up here," says Special Agent James M. Maddock.

So, for the Sund and Pelosso families, the agonizing uncertainty continues. On March 21 agents led Carole Sund's parents, Carole and Francis Carrington, and Silvina's parents, Raquel and José Pelosso, down a muddy trail to the place where the car had been found, 84 miles from Yosemite. There the four wept, prayed and laid a floral cross. "They were cut off in the prime of life," says Carole Carrington, 64, of the victims. "Julie was so excited about growing up. She had filled out an application for her driver's license. We need to find out who did this."

Investigators say that could take time. They have yet to find a third body, and the FBI has not publicly named any suspects in the case. But after a month of living in a motel near search headquarters in Modesto, the Pelossos, who run a soft-drink bottling plant in Argentina, have arrived at one conclusion. Given the unstinting generosity of strangers who have given them food and clothing, Raquel says the killers could not be typical Americans. "Where do they come from?" she asks. "Hell, I think."